Quality Of Service Criteria Research Articles

A relaxable service selection algorithm for QoS-based web service composition

Context: Web Services are emerging technologies that enable application to application communication and reuse of autonomous services over Web. Composition of web services is a concept of integrating individual web services to conduct complex business transactions based on functionality and performance constraints Objective: To satisfy user requirements, technologies of Quality of service (QoS)-based web service composition (QWSC) are widely used to build complex applications by discovering the best-fit web services in term of QoS. Method: In this paper, a QoS-based service selection (RQSS) algorithm is proposed to help composite web application development by discovering feasible web services based on functionalities and QoS criteria of user requirements. The RQSS recommends prospective service candidates to users by relaxing QoS constraints if no suitable or available web service could exactly fulfill user requirements. Results: A generic framework is implemented to demonstrate the feasibility and performance of RQSS by adapting WS-BPEL standards, and can be reused for QoS-based web composition applications. Conclusion: The experimental results show that the RQSS algorithm indeed performs well and increases the system availability and reliability.

Towards efficiency of QoS-driven semantic web service composition for large-scale service-oriented systems

Quality-of-Service (QoS) performance guarantee for service-oriented systems (SOS) has become a critical problem. With the increasing number of offered services comes the challenge of efficiently building large-scale SOS to meet the required QoS criteria. Optimization of QoS-driven semantic Web service composition is known to be NP-hard. We address the efficiency issue by developing a polynomial time algorithm (QDA) for shortest sequence composition. We use dynamic programming to find service candidates for each execution. When all the services are searched, we use a depth-first trace back to derive the execution plan. We have tested our approach under Web-scale demands 20,000 services and 150,000 semantic concepts. In comparison with existing approaches, our experimental results show that QDA can be used to solve large-scale service composition problem effectively and efficiently with QoS guarantee.

A user centric service-oriented modeling approach

With rapid development of service-oriented architecture and cloud computing, web services have been widely employed on the Internet. Quality of Service (QoS) is a very important criterion for service consumers to measure and select services. The selection of web services with respect to non-functional QoS criteria can be considered as a Multiple Criteria Decision Making (MCDM) problem when multiple consumers need to share a number of services. This paper describes a new user centric service-oriented modeling approach which is featured by integrating fuzzy Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) and Service Component Architecture (SCA) to facilitate web service selection and composition and to effectively satisfy a group of service consumers' subjective requirements and preferences in the dynamic environment. The main contribution of this method is able to translate a group of users' fuzzy requirements to services as well as model different levels of hardware and software as services to meet the requirements. We also design a simulated environment that includes 8*8 LED matrix on a circuit board that corresponds to an office with different appliances to demonstrate the dynamic service selection and binding. The simulation is used to assess the computational efficiency of the fuzzy TOPSIS method and the effectiveness of the proposed system.

A Flexible Tool for Web Service Selection in Service Oriented Architecture

Web Services are emerging technologies that enable application to application communication and reuse of services over Web. Semantic Web improves the quality of existing tasks, including Web services discovery, invocation, composition, monitoring, and recovery through describing Web services capabilities and content in a computer interpretable language. To provide most of the requested Web services, a Web service matchmaker is usually required. Web service matchmaking is the process of finding an appropriate provider for a requester through a middle agent. To provide the right service for the right user request, Quality of service (QoS)-based Web service selection is widely used. Employing QoS in Web service selection helps to satisfy user requirements through discovering the best service(s) in terms of the required QoS. Inspired by the mode of the Internet Web search engine, like Yahoo, Google, in this paper we provide a QoS-based service selection algorithm that is able to identify the best candidate semantic Web service(s) given the description of the requested service(s) and QoS criteria of user requirements. In addition, our proposed approach proposes a ranking method for those services. We also show how we employ data warehousing techniques to model the service selection problem. The proposed algorithm integrates traditional match making mechanism with data warehousing techniques. This integration of methodologies enables us to employ the historical preference of the user to provide better selection in future searches. The main result of the paper is a generic framework that is implemented to demonstrate the feasibility of the proposed algorithm for QoS-based Web application. Our presented experimental results show that the algorithm indeed performs well and increases the system reliability.

Introducing Quality of Service Criteria into Supply Chain Management for Excellence

Introducing Quality of Service Criteria into Supply Chain Management for Excellence

Introducing Quality of Service Criteria into Supply Chain Management for Excellence

This article is focused on a sub domain of quality, namely, quality of service. Considering supply chain management, the authors believe that it is important to distinguish between a quality of product (also service) offered by producers and service providers and a quality of service which is achieved between any supplier and customer, not only a consumer, along a supply chain. Quality of product represents producer’s/service provider’s commitment and is subject of various quality certificates issued by inspection authorities. This research examines the quality of service, which is provided by a supplier to its customer along the supply chain, between any pair of chain elements fulfilling this relation, including the common retailer-consumer relation. The authors introduce measurement points into a consumer-centric supply chain model for the defined criteria and defined the method of their monitoring and overall supply chain quality of service evaluation. Finally, the authors assess the envisaged impact of the results of their measurements on supply chain excellence, providing management with an opportunity to identify weak spots.

Multihop Nonregenerative MIMO Relays— QoS Considerations

For nonregenerative multihop multiple-input multiple-output (MIMO) relay communication systems, the optimal source precoding matrix and the optimal relay amplifying matrices have been recently established for a broad class of objective functions subjecting to the transmission power constraint at each node. However, existing works do not consider any quality-of-service (QoS) constraints, which are important in practical communication systems. In this paper, we derive the optimal source and relay matrices of a multihop MIMO relay system that guarantee the predetermined QoS criteria be attained with the minimal total transmission power. In particular, we consider two types of receivers at the destination node: the linear minimal mean-squared error (MMSE) receiver and the nonlinear decision feedback equalizer (DFE) based on the MMSE criterion. We show that for both types of receivers, the solution to the original optimization problem can be upper-bounded by using a successive geometric programming (GP) approach and lower-bounded by utilizing a dual decomposition technique. Simulation results show that both bounds are tight, and to obtain the same QoS, the MIMO relay system using the nonlinear MMSE-DFE receiver requires substantially less total transmission power than the linear MMSE receiver-based system.

Wireless sensor and actuator networks: Enabling the nervous system of the active aircraft

The ever increasing volume of air transport necessitates new technologies to be adopted by the flight industry to fulfill the requirements of safety, security, affordability, and environmental friendliness while still meeting the growing demand. What we need to achieve this goal is a new type of aircraft cruise control, interconnecting all the onboard active control systems and making more accurate control decisions than is currently possible, thus improving overall flight efficiency. Active Aircraft envisions such a nervous system of distributed wireless sensor and actuator network components, enabling the early detection of potential problems and quick, accurate reactions to these. As part of this vision, WSANs deployed on aircraft wings help reduce aerodynamic drag and significantly reduce fuel consumption. In this article we first describe this conceptual change in aircraft control technology. We then introduce a WSAN application to reduce skin friction drag and a network topology to enable it. In our application WSANs form virtual flap arrays on the wings to measure the skin friction in real time and to react using synthetic jet actuators, which suck and expel air on the wing to reduce the friction. The Active Aircraft vision imposes stringent performance requirements on the underlying WSAN communication algorithms. The medium access control and routing protocols, in particular, must meet the quality of service criteria set by active control applications. Thus, we also present the application characteristics of Active Aircraft and raise the issue of design considerations with regard to the communication protocols.

Technologies for the Electronic Distribution of Information Services - A Value Proposition Analysis

Since the original design and deployment of the Internet architecture, the economical and technological requirements regarding the distribution quality of web-based information services have changed drastically. Business models have evolved that particularly address quality and cost aspects of information service distribution, e.g. content delivery networks and peer-to-peer distribution. In addition, network operators apply differentiated routing technologies in dedicated infrastructures to guarantee a superior quality of service (QoS). This article compares the value propositions of technologies for information service distribution. 103 information services were analyzed by means of discriminant analyses in order to identify the main aspects influencing delivery quality and costs. The results indicate that the value propositions differ with regard to the type of services they support rather than with regard to direct QoS criteria, such as latency and packet loss. The insights derived from this work support information service vendors in their choice of a distribution provider.

TQoS: Transactional and QoS-Aware Selection Algorithm for Automatic Web Service Composition

Web Services are the most famous implementation of service-oriented architectures that has brought some challenging research issues. One of these is the composition, i.e., the capability to recursively construct a composite Web service as a workflow of other existing Web services, which are developed by different organizations and offer diverse functionalities (e.g., ticket purchase, payment), transactional properties (e.g., compensatable or not), and Quality of Service (QoS) values (e.g., execution price, success rate). The selection of a Web service, for each activity of the workflow, meeting the user's requirements, is still an important challenge. Indeed, the selection of one Web service among a set of them that fulfill some functionalities is a critical task, generally depending on a combined evaluation of QoS. However, the conventional QoS-aware composition approaches do not consider the transactional constraints during the composition process. This paper addresses the issue of selecting and composing Web services not only according to their functional requirements but also to their transactional properties and QoS characteristics. We propose a selection algorithm that satisfies user's preferences, expressed as weights over QoS criteria and as risk levels defining semantically the transactional requirements. Proofs and experimental results are presented.

Adaptive Distributed Fair Scheduling for Multiple Channels in Wireless Sensor Networks

A novel adaptive and distributed fair scheduling (ADFS) scheme for wireless sensor networks (WSN) in the presence of multiple channels (MC-ADFS) is developed. The proposed MC-ADFS increases available network capacity and focuses on quality-of-service (QoS) issues. When nodes access a shared channel, the proposed MC-ADFS allocates the channel bandwidth proportionally to the packet's weight which indicates the priority of the packet's flow. The packets are dynamically assigned to channels based on the packet weight and current channel utilization. The dynamic assignment of channels is facilitated by use of receiver-based allocation and alternative routes. Moreover, MC-ADFS allows the dynamic allocation of network resources with little added overhead. Packet weights are initially assigned using user specified QoS criteria, and subsequently updated as a function of delay and queued packets. The back-off interval is also altered using the weight adaptation. The weight update and back-off interval selection ensure global fairness is attained even with variable service rates.

QoS-Aware Service Selection Algorithms for Pervasive Service Composition in Mobile Wireless Environments

The successful application of pervasive services running in mobile wireless networks and devices relies on its ability to provide efficient and cost-effective QoS (Quality of Service) support. This paper proposes a comprehensive QoS model specifically for pervasive services. It considers not only user-perceived factors but also mobile wireless network characteristics. The corresponding formula to calculate each QoS criterion is also devised. In particular, this paper formulates the QoS-aware service selection problem for pervasive service composition and proposes some solutions to the problem, i.e., global-search-based LOSSA (local optimal service selection algorithm) and limited broadcast based LOSSA-k. The evaluation results of the algorithms have shown the effectiveness of the QoS model and the efficiency of the proposed LOSSAs.

Design and performance analysis of an inductive QoS routing algorithm

Routing mechanism is key to the success of large-scale, distributed communication and heterogeneous networks. Consequently, computing constrained shortest paths is fundamental to some important network functions such as QoS routing and traffic engineering. The problem of QoS routing with multiple additive constraints is known to be NP-complete but researchers have been designing heuristics and approximation algorithms for multi-constrained paths algorithms to propose pseudo-polynomial time algorithms. This paper introduces a polynomial time approximation quality of service (QoS) routing algorithm and constructs dynamic state-dependent routing policies. The proposed algorithm uses an inductive approach based on trial/error paradigm combined with swarm adaptive approaches to optimize lexicographically various QoS criteria. The originality of our approach is based on the fact that our system is capable to take into account the dynamics of the network where no model of the network dynamics is assumed initially. Our approach samples, estimates, and builds the model of pertinent aspects of the environment which is very important in heterogeneous networks. The algorithm uses a model that combines both a stochastic planned pre-navigation for the exploration phase and a deterministic approach for the backward phase. Multiple paths are searched in parallel to find the K best qualified ones. To improve the overall network performance, a load adaptive balancing policy is defined and depends on a dynamic traffic path probability distribution function. We conducted a performance analysis of the proposed QoS routing algorithm using OPNET based on a platform simulated network. The obtained results demonstrate substantial performance improvements as well as the benefits of learning approaches over networks with dynamically changing traffic.

DiffServ Aware MPLS Traffic Engineering for ISP Networks: State of the Art and New Trends

In the recent ten years, with the development of new applications through Internet such as multimedia or networked control applications, users need more and more quality of service (QoS). However, the requested QoS is not the same depending on the application. Most of the new models to manage internet traffic are based on specific QoS criteria which should be optimized. This paper presents main multiprotocol label switching (MPLS) approaches such as MPLS adaptive traffic engineering (MATE), load distribution in MPLS (LDM) and load balancing over widest disjoints paths (LBWDP) that are new models for traffic engineering. It also introduces periodic multi-step (PEMS) algorithm that adapts the offered quality depending on the class of the routed traffic.

Scheduling in IEEE 802.16e mobile WiMAX networks: key issues and a survey

Interest in broadband wireless access (BWA) has been growing due to increased user mobility and the need for data access at all times. IEEE 802.16e based WiMAX networks promise the best available quality of experience for mobile data service users. Unlike wireless LANs, WiMAX networks incorporate several quality of service (QoS) mechanisms at the Media Access Control (MAC) level for guaranteed services for data, voice and video. The problem of assuring QoS is basically that of how to allocate available resources among users in order to meet the QoS criteria such as delay, delay jitter and throughput requirements. IEEE standard does not include a standard scheduling mechanism and leaves it for implementer differentiation. Scheduling is, therefore, of special interest to all WiMAX equipment makers and service providers. This paper discusses the key issues and design factors to be considered for scheduler designers. In addition, we present an extensive survey of recent scheduling research. We classify the proposed mechanisms based on the use of channel conditions. The goals of scheduling are to achieve the optimal usage of resources, to assure the QoS guarantees, to maximize goodput and to minimize power consumption while ensuring feasible algorithm complexity and system scalability.

Dynamic management of quality of service with priority for multimedia multicasting

We propose a receiver-oriented resource reservation mechanism, called dynamic management of QoS with priority (DMQP), for multimedia multicasting over the internet that provides quality of service (QoS) guarantees with service differentiation for heterogeneous users. In the DMQP protocol, a real-time application requests QoS by specifying a range of acceptable bandwidth values and tolerable delay durations as opposed to rigid QoS criteria. The network strives to reserve resources for the application within its bandwidth range. The service differentiation is achieved by classifying the realtime applications (or end-users) into normal and prioritised users. When the number of end-users increases, all nodes, including the receiver, sender and intermediate nodes, readjust their reserved resources dynamically to admit the new end-users, as long as their minimum bandwidth requirement is met. The DMQP provides the flexibility needed for operation in the dynamic internet environment. It has significant benefit of allowing more flexible sharing of available resources among applications.

A navigation device with MAC supporting multiple physical networks for extended coverage and operations

This paper presents a novel consumer device that seamless integrates a VHF/UHF radio based mobile ad hoc network with GSM and Satellite networks. The device possesses the capability of operating in a wireless environment where multiple media covers patches of specified areas. The device acts like a universal communication gateway incorporating an intelligent communication controller and multiple physical interfaces for extended coverage. The controller is a cognitive cross-layer design that automatically selects and switches to most optimal network technology based on pre-defined Quality of Service criteria. This cognitive controller keeps communicating nodes connected to the vehicular network. A hybrid zone based QoS aware routing mechanism for multiple physical interfaces and networks is also presented. The device supports two GSM networks, one Satellite carrier, 802.11 interface and VHF or UHF modems including a GPS receiver. Such devices find applications in emerging Wireless Access in Vehicular Environment.

Service selection and workflow mapping for Grids: an approach exploiting quality‐of‐service information

AbstractThe advent of heterogeneous and distributed environments, such as Grid environments, made feasible the solution to computational‐intensive problems in a reliable and cost‐effective manner. In parallel, workflows with increased complexity that require specialized systems to deal with them are emerging, so as to carry out more composite and mission‐critical applications. In that rationale, quality‐of‐service (QoS) issues need to be tackled in order to ensure that each application satisfies the corresponding user requirements. Therefore, considering the quality provision aspect as fundamental for enabling Grid applications to become QoS compliant, we present an approach for service selection using QoS criteria. The latter is achieved with a suite of components that allow the different mappings of application workflow processes to Grid services that not only meet the user goals and requirements but also maximize his/her benefit in terms of the offered QoS level. We also demonstrate the operation of the aforementioned suite of components and evaluate its performance and effectiveness using a Grid scenario, based on a 3D image rendering application. Copyright © 2008 John Wiley & Sons, Ltd.

Cross-Layer Optimization for Multimedia Traffic in CDMA Cellular Networks

We consider the uplink transmission of multimedia services in a cellular network where multiple access is implemented by code division multiple access (CDMA) and the base station performs successive interference cancellation (SIC) to enhance performance. We propose a cross-layer optimization technique that operates both at the physical layer, by selecting the detection order at the SIC receiver, and at the medium access control layer, by selecting the power/rate for each mobile terminal. The optimization objective is the maximization of the overall weighted network throughput with the satisfaction of the quality of service criteria for multimedia communications. The resulting problem turns out to be NP-complete and we resort to a discrete stochastic approximation (DSA) approach for its solution. Concerning DSA, an efficient implementation is proposed in order to reduce memory occupation and improve the convergence of the algorithm. In a UMTS cellular environment, numerical results show that the optimization provides a significant performance advantage over existing techniques at the cost of an increase of computational complexity and memory occupation.

Utility-based QoS optimisation strategy for multi-criteria scheduling on the grid

The paper presents quality of service (QoS) optimisation strategy for multi-criteria scheduling on the grid, based on a mathematical QoS model and a distributed iterative algorithm. Three QoS criteria are considered, namely payment, deadline and reliability, which are formulated as utility function. The optimisation problem is split into two parts: task optimisation performed on behalf of the user and resource optimisation performed on behalf of the grid. The strategy employs three types of agents: task agents responsible for task optimisation, computation resource and network resource agents responsible for resource optimisation. The agents apply economic models for optimisation purposes. Dynamic programming is used to optimise the total system utility function in terms of an iterative algorithm. The objective of multi-criteria scheduling is to maximise the global utility of the system. This paper proposes an iterative scheduling algorithm that is used to perform QoS optimisation-based multi-criteria scheduling. The proposed QoS optimisation-based multi-criteria scheduling problem solution has been practically examined by simulation experiments.